A bulk box or bin is a large container normally used for bulk shipment of flowable materials, e.g. plastic resin, chemicals, powders, vegetables, etc. The range of capacities for this class of containers is about 800-2200 lbs., however, the most common size is about 1000 lbs. Often, during storage, several of these relatively large boxes are loaded one on top of the other in multi-tier fashion.
The stacking strength needed for multi-tier storage of bulk boxes is achieved by reinforcing the side walls of the container with additional plies of corrugated material, commonly called liners. In order for the multiple layers of material in the construction of the box to be effective, it is essential that the plies be tightly bonded to one another with adhesive. In addition, the inner reinforcement must be accurately placed relative to the outer blank to insure that, in the erected condition, the loading will be distributed equally to all sides of the box.
Bulk boxes vary in size and construction depending on the specific application. The corrugated material may be constructed using a variety of flutes and basis weights of constituent parts, as well as a number of inner reinforcing plies or liners. While the most common box is a rectangular design, boxes having as many as eight sides have been employed. The outer blanks of bulk boxes can range in size from 43 to about 96 square feet. A finished box can weigh as much as 40 lbs. in the unloaded condition. The size and weight of the component parts has resulted in a very slow and frequently labor intensive manufacturing process.
One such assembly process is described in my patent, U.S. Pat. No. 3,964,953, which is hereby incorporated by reference. This prior art procedure provides an apparatus which alternatively picks up and places liners and blanks in acceptable registration for lamination. This is accomplished, in part, by a vacuum cup suspension system in combination with the shuttle arrangement. A glue spray station is also used to apply adhesive to the liner prior to assembly.
While prior art bulk box manufacturing has produced acceptable product, there is still a need for higher quality and greater productivity. The assembly operation requires high accuracy to assure that the liner and blank align properly to provide optimum strength. However, current alignment procedures can be inconsistent, and overspray from glue spray stations can often complicate the maintenance of the system.
Accordingly, there is a current need for a highly accurate and fully automated blank-liner assembly apparatus.